XML Hacks

Include External Documents with XInclude

Beyond entity inclusion, there is another mechanism for including external text and documents. It’s called XInclude.

XML Inclusions, or XInclude, is still a working draft specification at W3C (http://www.w3.org/TR/xinclude/), but it is being implemented with reasonable confidence as a step up from external entities. XInclude allows on-the-spot replacement of text or markup, without a DTD or entity reference. It also has a fallback mechanism in case something goes haywire.

The main feature of XInclude is the include element. The namespace name for XInclude is http://www.w3.org/2001/XInclude, and the common prefix is xi.

Tip

This hack is based on the November 2003 working draft of XInclude (http://www.w3.org/TR/2003/WD-xinclude-20031110/). The candidate recommendation for XInclude was issued in April 2004, just as I was finishing this book. The candidate rec specifies a previous namespace name, http://www.w3.org/2001/XInclude. I am using the older namespace URI so that it works with the software I’m using here, but it’s likely that the software will catch up with the current version of the specification soon, and you’ll have to change the namespace URI to get it to work.

The include element has seven possible attributes: href, xpointer, parse, encoding, accept, accept-charset, and accept-language. The href attribute is mandatory unless xpointer is present (and vice versa), because you have to point to the included text or markup using one or the ...